The Banzai Falls Splash Blast Lagoon is an inflatable water slide you can put in your backyard.
I picked this up for my kids, because I knew they’d love it, and also so I could have some vicarious fun just watching, since they didn’t have cool stuff like this when we were kids.
My three girls are crazy about this water slide – they’ll play on it for hours at a time. Not only is it fun, but it knocks them out and makes it easier to put them to sleep. 
As you might be wondering, yes, I did try the water slide myself.
According to the instructions, I was too big for it, but I couldn’t resist. And I loved it just as much as the kids did.